Twitter is a social media and social networking service that allows users to broadcast short posts known as tweets. These tweets can contain text, videos, photos, or links. Twitter is a microblogging service, which is a combination of blogging and instant messaging, for registered users to post, share, like, and reply to tweets with short messages. Non-registered users can only read tweets. Twitter is used to share information quickly, and because tweets can be delivered to followers in real-time, they might seem like instant messages to the novice user. However, unlike instant messages that disappear when the user closes the application, tweets are also posted on the Twitter website. They are permanent, searchable, and public. Twitter was created by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams in March 2006 and was launched that July.

Twitter allows registered users to post text, images, and videos. Users can post (tweet), like, repost (or retweet), quote, or comment on posts, and direct message other registered users. Users interact with Twitter through browser or mobile frontend software or programmatically via its application programming interfaces (APIs) . People use Twitter to get the latest updates and promotions from brands, communicate with friends, and follow business leaders, politicians, and celebrities. They also use it to stay current on news and events. Twitter is used by PR teams and marketers to increase brand awareness and delight their audience.

Twitter was the first source to break the news of the water landing of US Airways Flight 549 in New York Citys Hudson River. Twitter is an online news and social networking site where people communicate in short messages.